This invention relates generally to hot presses and, more particularly to, single unit portable hot presses.
Many processes are known in the art for forming metallic parts. These processes include, among others, milling, stamping and pressing. The use of a hot press to form metallic parts is often preferred over other forming processes. However, current hot press designs and their resulting forming processes are relatively inefficient. Additionally, current hot press technology poses safety hazards to press operators and press equipment.
Typical hot presses are large, multi-unit machines. Each machine includes a press unit, a control unit, and a hydraulic unit. Each unit is typically a stand-alone unit with minimal interconnection between the units. Consequently, each machine occupies a significant volume of shop space. Moreover, the volume of space typically occupied by each machine exceeds by orders of magnitude the size of part being produced. Additionally, to move the machine, each unit must be disconnected from the other units, moved separately, and subsequently re-connected. Thus, not only do current hot presses inefficiently utilize space, but they also require excessive time and effort to relocate.
Thermal inefficiencies are another drawback of current hot presses. The thermal inefficiencies are derived from several sources. Heated platens employed by the press typically are not adequately insulated and only heat a single surface of the die. Also, the lack of insulation surrounding the platens results in excessive heat loss, which requires additional energy to achieve and maintain die temperature. The single heating point design requires additional time to achieve a desired thermal equilibrium throughout the die. Additionally, current hot presses include large access doors that must be opened to insert or remove the parts to be formed. The large doors allow a massive amount of heat loss every time they are opened. This problem is compounded because these same presses lack structure to align the die within the press during die loading, the doors must remain open for an excessive length of time during the part and die loading process. Consequently, considerable time is spent, and thus heat energy lost, while manually positioning the part and die in the press.
Current hot press designs create a number of safety hazards. The lack of adequate insulation surrounding the heating platens results in a considerable amount of convective heat being radiated. Consequently, an operator is required to wear a great deal of thermally-resistive safety clothing and equipment. This safety equipment is generally uncomfortable and cumbersome to wear. Further, the cumbersome nature of the equipment potentially creates additional hazards by inhibiting the operator""s movement.
Standard hot presses employ a downward directed press motion that creates another safety hazard. The downward directed press movement requires elements of the hydraulic unit to be above the heated platens. Thus, any leaking of hydraulic fluid from the hydraulic unit can contact the heated platens creating a fire hazard.
Thus, there is an inert need in the art for a hot press that efficiently uses space, is thorough, efficient, and overcomes safety hazards posed by current hot presses known in the art.
The present invention is a hot press that efficiently uses space, is thermally efficient, and overcomes safety hazards associated with known hot presses.
The present invention is a portable, compact hot press. The hot press includes a frame that has a press unit attached thereto. The press unit has a crown plate, a bolster plate, and a base plate. An upper press unit is attached to the crown plate and a lower press unit is attached to the bolster plate. The lower press unit is configured to contact the upper press unit when the press is in a closed position. The press further includes a control unit attached to the frame. The control unit is configured to manually or automatically control press operation. Additionally, the press includes a hydraulic unit that is attached to the frame and is configured to facilitate motion of the press operation.
Another aspect of the present invention is a method of operating a compact hot press. A part is loaded into the press. The part is preheated to a predetermined temperature. After the press is preheated, the press is closed and the part is placed under load. The load is maintained for a predetermined time. At the expiration of the predetermined time, the press is opened and the part is removed.